A method for filtration of harmful gas effluents from an industrial installation including the steps of providing a gas effluent from an industrial installation, the gas effluent including a mixture of gases; filtering the harmful, elements from the gas effluent by membrane separation through a plurality of membranes, the membrane separation being achieved by sifting, sorption and/or diffusion, each membrane being adapted for filtering a specific harmful element; sorting the filtered harmful elements and storing them in separate storage reservoirs, and discharging the processed gas effluent to the atmosphere.